Fuel composition and method of preparing the same



S P. MILLER June 30, 1931.

EUEL COMPOSITION AND METHOD OF PREPARING THE SAME Filed July 16, 1927 m- P INVEN OR W W ATTORNEYS Patented June 30, 1931 UNITED STATES PATENT oFFIcE srnanr rmnnnn MrLLEn, of surnames, NEW miasnv; AssIGNon 'ro BAR- nm'r COMPANY, on NEW YORK, 11., n, A conrorwrron or m JERSEY FUEL COMPOSITIONAND METHOD OF PREPARING m Application filed July 16,

I sition and to an improved method of producof the .free or relatively free from tar aci 'rectly produced without theaid of distillaing it. I

The new fuel composition of the present invention is made up of coke oven tar freed from all or from a considerable part. of the tar acids normally contained in such tar and otherwise containing tar constituents normal to coke oven tar. Inparticular, the new fuel composition is substantially free from decomposition products produced by distilling tar in ordinary stills with resulting, decomposition of some of the tar constituents and resulting increase in pitch and carbon content. r

The improved method of producing the new fuel composition includes the production of tar acids as one of the valuable, products recess.

.Ordmary coal tar from by-product coke oven plants contains tar acids in substantial amounts. These tar acids cannot, however, be directly separated from the tar. In order to efiect their se aration, the tar is subjected to distillation in tar stills and the distillate oil is then subjected to treatment for the extraction of tar acids therefrom. Such distillation of the tar is accompanied by substantial decomposition of oil constituents, including constituents which would otherwise be contained in the tar acid oil. 7 If the distillation of the tar is carried to a .sufiiciently high temperature to secure higher -tar= acidsor phenols, the decomposition is increased. Such increase indecompositlon 1S accompanied by increase in carbon content of the pitch residue resulting from the distillation. a

The present invention provides an improved process whereby a fuel comsisosition is di tion, and with the avoidance of decomposition resulting therefrom, and with the production of a fuel tar free from all or'from a considerable part of the tar acids normally contained therein, but otherwise containing undecomposed constituents normally present in the co e oven tar. H

According to the present invention, the hot from tar acids which form product of the process.

1927. Serial No. 206,869.

coke 'oven gases as they come from the coke .ovens are cooled to a re ated temperature which is still sufiiciently high to maintain the greater part or all of the tar acids in the form of vapors, and the gases are treated at such temperature with an electrical precipitator or with other means for separating therefrom the heavier tar and pitch constit uents, while leaving the tar acid oils in the form of vapors. gases separates therefrom a pitch product which is employed as one of the components Such treatment of the of the new fuel composition, and which is free from increased carbon content due to subsequent distillation. The hot gases after cleaning to separate heavier tar and pitch constituents therefrom are then cooled to separate clean taracid oils, either as a single fraction or a plurality or fractions. These clean oils, being free from heavier; tar and pitch constituents, can be directly extracted,

for example, with caustic soda solution, to

separate tar acids, therefrom, leaving a neutral oil. Naphthalene can also, if desired be separated from such oil. The neutral oil so produced is returned and admixed with the directly recovered pitch residue to form the new composite fuel composition, which will; I be made up of the separated itchconstituents and of the neutral oil; 0th of these component products are directly recovered products, which have not been subjected to furtherdistillation, and which are accord- ,ingly free from decomposition products produced by such further distillation. The new composltion. is also free, or relatively free, U another valuable In the carrying out of the process the hot coke oven gases,'which leavethe co e ovens at a high temperature, around600 to 700 C., or higher, are-cooled to a limited extent, for example, by ammonia liquor sprayed therein in the ordinary collector main, or by ammonia liquor and tar. The cooling of the gases is regulated so that the tar acid oils are largely or completely retained in the vapor stated. The cooling of the ases with ammonia liquor, or'with ammonia 'quor and tar, in the ordinary collector main, will, due

men

to local cooling in contact with the ammonia liquor, result in throwing down a heavy tar which may contain a small amount of the tar.

however, to obtain an increased yield of taracids, the gases should be kept at a higher temperature, for example, around 125 (J- or 150 C. by regulated cooling thereof.

The hot coke oven gases, after "regulated cooling thereof, are subjected to a cleaning treatment for the separation of the entrained tar and pitch constituents therefrom. This cleaning treatment is advantageously a treatment in an electrical precipitator, which will remove from the gases suspended solid and liquid particles, while leaving the vapors in the gases passing from the precipitator. In-

stead of using an electrical precipitator, a

hot pitch scrubber can be employed, employing pitch of-a composition and temperature corresponding to that carried in suspension in the gases. By a sufliciently intimate contact of the scrubbing pitch with the gases, substantially all of the suspended pitch particles can be separated therefrom, leaving a clean gas freed from suspended pitch constituents and stillcontaining tar acid oils in vapor form.

Such treatment of the gases-will result in theseparation therefrom of pitch, which will be free or relatively free from tar acids, and

which will difler from ordinary pitch pro.-

duced by the distillation of tar in ordinary tar stills. It will be free from decomposition products produced by such distlllation,

and it will have a low carbon content. This directly recovered'pitch product, low in carbon and free from such decomposition products, is employed in the new fuel compositlon of the present invention.

The cleaned gases, after separation of suspended pitch therefrom, are subjected to further cooling to separate tar acid oils therefrom. If, for example, the gases are cleaned at a temperature of 150 C. and subsequently subjected to cooling, therewill be separated an oil containing constituents boiling over a considerable range of temperature and containing both the higher and the lower tar acids. If the gases are subjected to cleaning at a lower temperature, they may contain less of the higher boiling tar acids, but will still contain the greater part of the tar acid content of the coke oven gases, and particularly the lighter tar acids, such as are conta ned By carrying out the cooling in stages, a

heavier and a lighter tar acid oil can be obtained, containing respectively higher and lower boiling tar acids. The gases after the separation of the tar acid oil can then be passed to an ammonia saturator or scrubber for the absorption and recovery of ammonia therefrom; and the gases can thereafter be subjected to scrubbing for the recovery of benzol and other light oils.

The extraction of the tar acids from the tar acid oils can be effected in apparatus of the kind commonly usedfor extracting tar acids from distillate oils, .using an aqueous solution of caustic soda or other phenol-abs'orbing reagent. and bringing about intimate contact of the oil with the caustic alkali solu- 7 tion to cause combination of the phenols or tar acids-with the caustic alkali. A solution containing ten percent of caustic soda can be employed for such tar acid extraction, although a more dilute or a more (10110611? trated solution, for example, a solution of from 25 to 35 percent strength can be employed.

The solution of tar acids in the caustic alkali can then be treated for the separation 1 of the tar acids, for example, by treating with carbondioxide to set free the phenols and to form a solution containing sodium carbonate; and the completion of the process can be efi'ected by adding a small amount of sulphuric acid to the crude tar acids after separation from the sodium carbonate solution. Before the taracids are set free from the carbolate solution, the solution may be subj ected to distillation to remove other volatile constituents therefrom, such as pyridine bases, naphthalene and other dissolved oils.

The tar acids separated from the carbolate solution may be subjected to further distillation and refining to give commercial tar acid products.

. he oil remaining after the extraction of the tar acids will be substantially free of tar acids. It may be rich in naphthalene, in which case the extraction of the tar acids should be at a sufficiently high temperature to maintain the naphthalene in .a liquid state. Theextracted oil containing the naphthalene may be subjected to a cooling or chilling operation to separate part of the naphthalene therefrom, 'which may thus constitute a product of the process in a relatively pure form.

. The extracted oil, either with or without separation of naphthalene therefrom, is emheavier oil fraction may, for example, be

, stills and in particular will be low in carbon,-

valuable as a creosoting material, or as an ingredient of creosoting composition, in which case only the neutral oil from the lighter oil fraction can be returned for mixture with the directly recovered pitch. v

The new composite product thus produced will accordingly be made up in part of di-v rectly recovered pitch, directly "recovered from hot coke oven gases, and in part of; neutral oil, ifilSO directly recovered from such gases after the separationof itch therefrom, and after the extraction 0 tar acids from the separated oils, and it may also be made up in part of the heavy tar from the collector main. The new composition will be free from increased carbon content due to furtherdistillation in ordinary tar so that it can advantageously be stored and used without danger of separation of carbon therefrom, either in the storage tanks or in. the pipe lines leading to the fuel burners.

The blending of the directly recovered pitch with the neutral oil can be carried out 1n an ordinary tank with suitable agitation to insure uniformity of intermixture; or the neutral oil and the directly recovered pitch can be run together into a mixing receptacle continuously, to bring about continuous blending or intermixture. If the directly recovered pitch is mixed hot with the neutral oil, it will tend to distill the lighter constituents from these oils, in which case the mixing chamber can be provided with a refluxing device to condense and return'anyoils s0 distilled. The directly recovered pitch readily blends with the'directly recovered neutral-v oil to form a uniform fuel composition.

The invention will be further described in connection with the accompanying drawing showing in a more or less diagrammatic manner a suitable apparatus forthe carrying out of the process of the invention and the production 'of the new fuel composition, but it will be understood that the invention is illustrated thereby and not limited thereto.

In the drawing, the coke oven block 5 has the usual uptake pipes 6 leading fromthe individual ovens to the collector main 7. The gases pass from the collector main through the center box 8 into the short main 9, which leads to the electrical precipitator 10.

the goose-necks and in the collector main the hot gases are sprayed through sprays 11 and 12 with ammonia liquor or ammonia and tar supplied from a suitable source through the pipe 13., The temperature'of the gases leaving the collector main is controlled by regulating the amount of sprayin Cooling of 1 the gases causes heavy tarto e thrown out in the collector main which, together with the ammonia liquor from the sprays, collects in the center box and is drawn oil into the decanter 14 from which the ammonia liquor is collected in the receiver 15 and tar is drawn off into the tank 16.

The precipitator' 10 is of. any suitable de sign. The drawing indicates a precipitator of the ty e shown 1n the co nding ap lication of McCloskey, Serial No. 16 ,338, which is especially designed for use with hot gases. The cooling is so regulated as described above that the gases passing through the precipitator will have a temperature of, for example, 125 C. or 150 C. In case a scrubber is employed for cleaning the gases,

the scrubbing medium may be pitch of a temperat-ure and composition corresponding to that of the particles removed from the gases during the cleaning operation, and with sufficiently intimate and thorough scrubbing to removepitch particles from the gases and leave clean gases'from which clean oils can be directly recovered by cooling.

.Thepitch thrown down in the precip-itator is draw off into the pitch receptacle 17 The hot gases leaving the precipitator pass to condensing means which in the drawing arerepresented by the two condensers 19 and 20. These condensers may be of the usual type used in by-product recovery apparatus such as. indirect condensers. in whch water is used as the cooling medium, without introducin it-into direct contact with the gases. The action thrown down in the first condenser is drawn ofi' into the storage tank 21 and by proper regulation of the cooling is of a'nature suitable for use in creosoting comsitions. The lighter fraction thrown down in the condenser 20 is drawn ofl' into the decanter 22 from which ammonia liquid is decanted into the receiver 23 and carbolic oils are drawn off into 24. From the condenser 20 the gases pass to the exhauster40 and to an ammonia absorber and light-oil scrubber (not shown). Both the heavy oil collected in 21 and the lighter oil collected in 22 can be extracted to recover tar acids therefrom, and the'neutral oils then blended with In the drawing, the tar acid extraction,

equipment is shown arranged for extracting "only the lighter oil, although it canbe simi-' larly employed when the total clean oil is to be extracted. The oils from 24-are delivered to the extraction apparatus 25 by means of pump 27 through pipe 26, and are mixed with caustic soda supplied through pipe 28. The extraction apparatus may be of any suitable type such as a cylindrical tank preferably with a conical bottom equipped with an agitator 29. After thoroughly mixing the caustic soda with the light oils, the mixture is allowed to settle and the solution of carbolates is separated from the extracted oils and collected in the storage tank 30 while the extracted oils are drawn off into the tank 31.

The extracted oils recovered in the tank 31 are valuable for blending with pitch and tar to form fuel compositions. By using pitch and tar which are low in free carbon a fuel composition may be prepared from which carbon, etc., will not settle out in appreciable amounts. The extracted oils are blended with the heavier products in the tank 32 to which they are supplied through the pipe 33 by pump 34. The pitch may be supplied through pipe 35 by pump 36. If hot pitch is used, the two ingredients will readily blend to give a uniform mixture. When hot pitch is used, light constituents from the extracted oils may be volatilized, in which case it is well to equip the mixing tank with a condenser such as is shown at 37, the condensate from which may be returned to the mixing tank. The mixing tank has an outlet 39 for the fuel mixture. The mixing tank may be provided with an agitator (not shown) for promotin the blending of the pitch and extracted o1 In addition to pitch from the precipitator, tar from the collector main may be supplied to the mixing tank through the pipe 38 in suitable proportions.-

The arrangement of apparatus illustrated for extracting tar acids from the light oil is equally applicable for the extraction of tar acids from the creosote oil or from the total clean oilcondensed from the gases, where all of the oils are condensed together and are to be extracted for the recovery of tar acids therefrom and the production of an extracted oil, which is to be blended back with the pitch residue.

The apparatus illustrated provides also for the treatment of only the lighter oils rich in tar acids to recover tar acids therefrom, and to give a light extracted oil for blending with the pitch residue, while iving heavier oils valuable for use directly or creosoting purposes, where they are not desired as part of the fuel composition. The blending of the light extracted oils with the pitch gives a fluid fuel composition, and one readily ignited because of the contents of light extracted oils. Where the entire clean oilrecovered from the gases is extracted to remove tar acids therefrom and the extracted oil is blended back with the pitch residue and with the heavy tar from the collector main, the new fuel composition will contain practically all of the constituents normal to ordinary coal tar except the tar acids removed therefrom. Where naphthalene, as well as tar acids, is removed, the fuel composition will similarly be freed from part or all of its naphthalene content. Where part of the directly recovered oil is employed as a creosote oil, the new composition will contain, the remaining normal constituents of the tar except for the creosote oil and the tar acids oritar acids and naphthalene, -extracted or separated from the oil which is blended with the pitch and heavy tar. 1

I claim:

1. A new fuel composition comprising pitch and neutral oil constituents normally contained in coal tar in a substantiallyundecomposed condition, said composition being free from the greater part of the tar acid constituents normally contained in the tar' but containing neutral oils having boiling points corresponding to those of the tar acids, and said composition being substantially free from decomposition products of the normal tar constituents.

2. The method of producing a fuel composition from hot coke oven gases, which comprises subjecting the gases to a regulated cooling to condense pitch constituents therefrom while leaving tar acid oils in the form of vapors, subjecting the gases to a cleaning treatment to separate suspended pitch particles therefrom at a temperature such that tar acid oils will be kept in the form of vapors, cooling the cleanedvgases to separate tar acidoil therefrom, extracting tar acids from'such oil, and blending the resulting neutral oil with the pitch directly separated from the hot coke oven gases.

3. The method of producing a fuel composition from hot coke oven gases which comprises subjecting the gases to a regulated cooling to separate pitch constituents therefrom at a sufiiciently high temperature to leave creosote oil and tar acid oil in the form of vapor, passing the gases into an electrical precipitator and sub ecting them therein to an electrical discharge to separate suspended pitchparticles therefrom, cooling the resulting cleaned gases to separate therefrom first a creosote oil and thereafter a tar acid oil, ex-

tracting tar acids from the tar acid oil and tator and subjecting them to an electrical discharge therein to separate pitch therefrom and to eave clean gases containing tar acid oil vapors, cooling the gases to separate tar 5 acid oil therefrom, extracting tar acids from such oil, and blending the resulting neutral oil with the pitch and tar directly recovered from the coke oven gases.

In testimony whereof I aflix my signature.

1o STUART PARMELEE MILLER. 

